A storage system includes a plurality of storage devices and a server device controlling them. In a scale-out type storage system, data rebalancing (data rearrangement) processing is executed among the storage devices in order to ensure leveling of data at addition of the storage device. In data rebalancing, data biased in the storage device is copied to another storage device in many cases. Thus, while data rebalancing is being executed, a network bandwidth and a system resource are used.
Regarding load distribution of a logical volume, the following logical volume load distribution technologies are known. In storage devices, a performance measurement mechanism measures a load situation of the logical volume on the basis of a data amount transferred by a data transfer mechanism and a command processing amount. A copy mechanism copies contents of a logical volume set to a physical volume to a logical volume set to a spare physical volume on the basis of the measurement result of the performance measurement mechanism. Load distribution of data access is executed by having a plurality of pieces of copied data.
Patent Literature 1: Japanese Patent Laid-Open No. 2006-053601
Patent Literature 2: Japanese Patent Laid-Open No. 2007-149068
Patent Literature 3: Japanese Patent Laid-Open No. 2005-284632
Patent Literature 4: Japanese Patent Laid-Open No. 2006-99748
Patent Literature 5: Japanese Patent Laid-Open No. 2004-5634
Patent Literature 6: Japanese Patent Laid-Open No. 2007-72538